Disclosed herein is a vehicle seat including a seat cushion and a seat back that rotates relative to the seat cushion, and particularly, to a vehicle seat including a link mechanism that interlocks another movable member with the seat cushion when it is rotating.
There are well known vehicle seats including a seat cushion and a seat back that rotate relative to the seat cushion, and among such vehicle seats, there is known a seat including a link mechanism for interlocking another movable member such as a seat cushion position adjusting mechanism with the seat back when it is rotating. Further, some of such vehicle seats including the link mechanism further include a rotation body that rotates to interlock the another movable member with the seat cushion, as a component. In the vehicle seat with such a configuration, the aforementioned rotation body rotates in a predetermined direction by being pressed by the rotating seat back. The rotation body is connected to the another movable member by a wire or a gear set. For this reason, when the rotation body rotates, the rotation thereof is used as a driving force and thus the another movable member is driven.
An exemplary configuration which has been devised for supporting the aforementioned rotation body in the vehicle seat is a configuration in which a shaft is provided in a plate member connecting a side surface of a seat cushion to a side surface of a seat back and the rotation body is rotatably supported by the shaft (for example, see Japanese Patent Document No. H01-123736 (“the '736 Document”).
In the configuration disclosed in the '736 Document, the side surface of the seat back is provided with a protrusion and a through-hole is formed along the rotation track of the seat back in the plate member. The protrusion which is provided in the side surface of the seat back is engaged with the through-hole, and is disposed in a state where the front end portion thereof slightly protrudes from the through-hole. When the seat back rotates in such a state, the protrusion which is provided in the side surface of the seat back moves along the through-hole formed in the plate member, and halfway through the movement, abuts against the rotation body. Subsequently, when the seat back further rotates and the protrusion moves toward one end portion of the through-hole, the front end portion of the protrusion is pressed against the rotation body. As a result, the rotation body rotates in the same direction while being interlocked with the seat back.
However, in the configuration disclosed in the '736 Document, in order to transmit the rotation of the seat back to the rotation body, the side surface of the seat back is provided with the protrusion and the protrusion is engaged with the plate member connecting the side surface of the seat cushion to the side surface of the seat back. That is, since the plate member is provided with the through-hole, the size of the plate member increases because of the installation space of the through-hole. As a result, the size of the vehicle seat increases. The size increase of the vehicle seat decreases the degree of freedom of the seat installation position inside the vehicle and affects the manufacturing cost.